The diabetes drugs Actos and Avandia raise the risk of heart failure but do not increase the risk of heart-related death, U.S. researchers said on Thursday, confirming earlier findings.

The popular drugs for treating type 2 diabetes have been the subject of numerous analyses - with more to come - as doctors attempt to weigh their risks following the May report that Avandia increased the risk of death by 64 percent and the risk of heart attack by 43 percent.

Both Actos, made by Takeda Pharmaceutical Co Ltd, and Avandia, made by GlaxoSmithKline, already carry U.S. Food and Drug Administration “black box” warnings that they may cause or worsen congestive heart failure, a chronic condition in which the heart fails to pump blood efficiently.

The latest study in the journal Lancet found heart failure risks are greatest for patients with a history of heart disease and heart failure, but less for those who had no heart problems. Overall the relative risk was 72 percent higher.

“The risk is across all types of patients but the risk ranges from very low to very high depending on the patient’s cardiac history,” Dr. Richard Nesto of the Lahey Clinic Medical Center in Burlington, Massachusetts, who led the study, said in a telephone interview.

Actos, known generically as pioglitazone, and Avandia, or rosiglitazone help the body use insulin more effectively. They are among several classes of drugs that treat type-2 diabetes, which affects 194 million people worldwide.

KNOWN RISK

Spokeswomen for both Glaxo and Takeda noted the congestive heart failure risk is not new to the class of drugs called thiazolidinediones. And they said the study did not find an increased risk of death, as did May’s New England Journal of Medicine analysis.

A study published in the Journal of the American Medical Association earlier this month suggested Actos actually cuts the risk of heart attack, stroke and death.

A separate study in the same issue found Avandia increased the risk of heart attack by 42 percent, and more than doubled the risk of heart failure after one year.

Like most of the prior research, the Lancet study is a meta-analysis, a type of study that pools data from many different clinical trials that have already been completed to get a picture of overall risk.

It looked at data from seven trials of drug-related heart failure in more than 20,000 patients with type 2 diabetes or pre-diabetes, who were given Actos or Avandia.

Editorials in the same issue of Lancet faulted studies that do not ask whether the drugs actually helped diabetes patients.

“All the meta-analyses fail to spot the elephant in the room. Treatments should be effective, rather than merely innocuous,” said Drs. John Cleland and Stephen Atkin of the University of Hull.

Doctors at the Mayo Clinic in Rochester, New York, and McMaster University in Canada said studies should prove drugs help diabetics feel better and live longer rather than narrowly focusing on lowering blood sugar.

“This policy will prevent the premature dissemination of therapies that ultimately prove harmful… and speed the day when we can confidently offer safe treatments that can provide important benefit to patients with diabetes,” Mayo’s Dr. Victor Montori and colleagues wrote.